From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E188C433FF for ; Mon, 29 Jul 2019 16:04:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 361CB21773 for ; Mon, 29 Jul 2019 16:04:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="so0RkHbQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727903AbfG2QES (ORCPT ); Mon, 29 Jul 2019 12:04:18 -0400 Received: from mail-wm1-f68.google.com ([209.85.128.68]:55524 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726795AbfG2QER (ORCPT ); Mon, 29 Jul 2019 12:04:17 -0400 Received: by mail-wm1-f68.google.com with SMTP id a15so54370596wmj.5; Mon, 29 Jul 2019 09:04:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=ZxCoxZNZqZ7BaNpp6YlaSGJX4F8d+cKr8ODCDAIBeo0=; b=so0RkHbQmktB6qvbzDiBKriLe/K5ptlYiSmQLEWl1HuGaXc5eKAH3MVFtwhZ3awKrZ blQZvJemfCUieBHxA0+RMJ0DcC9Aj5ClGQU2JDDQFl+b1iyHt1pxWfUD0EgInZgiwX17 cNR99Ep+c2x/jHPQmsiCV+MjZY/dSNEFqAAdnwS+1IqeSu2HaHxyRFTrYnI9cbB0XDJD 0Za/nyl2w1iJN3qQPuQZXqHL1/7cOtvfgjJWyJBLksgkHEur7WbXQDx5kp+4a8ViBHam 9B0YBxc5+nRTMUslC2e2RJr0VedelGAChxO1iyzKp3DYnfLHbdu2LxE2eFUSwaj8VFzV khFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=ZxCoxZNZqZ7BaNpp6YlaSGJX4F8d+cKr8ODCDAIBeo0=; b=CB1kgX5ytURUi6S+ptZ9FPubVVvM4L/uysId5Oj8pnz56LSNA34Yh+PJt9XiSjIpRP g48rDB3NjDBkzuQ1KY087zvj+GR+IMCsa8hpgrkL8+sWosBl8lYPPcttdzUm3KsUBH1Y tTDB6tjOlneJWKsxC6L2dc6JIhBo9tUsE3foCK1Z+l9QBbOJvsP8xyRMGoH6qTWbi+cY U+SKRoil/PaSIFArNm1HxFe/CvtcmTgy4yUOUm1WEetLWP4URz3JtHpNTdRbmRQcrLPg 8PPEVNBxgfrthTOlucIxknr5OVrv3//DZjzft957ebBQFWB4A3UcrY6bCA6L1jif0fz+ hqnQ== X-Gm-Message-State: APjAAAXbdThRHI5BbLUg5Au2updcSEsaZ9PefCd5WXiVZ/8dMna0NRRI fliueQOhebKs+rc3vxB+3Q8= X-Google-Smtp-Source: APXvYqzGLKYdNwB2KW7FyW6D9ipox2XB2mdajXe63NXSkTQIYI4BlIbqGc0hBM3uIt5TS50fgN4EgA== X-Received: by 2002:a7b:c144:: with SMTP id z4mr104465393wmi.50.1564416255100; Mon, 29 Jul 2019 09:04:15 -0700 (PDT) Received: from archlinux-threadripper ([2a01:4f8:222:2f1b::2]) by smtp.gmail.com with ESMTPSA id a81sm63363187wmh.3.2019.07.29.09.04.14 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Mon, 29 Jul 2019 09:04:14 -0700 (PDT) Date: Mon, 29 Jul 2019 09:04:12 -0700 From: Nathan Chancellor To: Masahiro Yamada Cc: linux-kbuild@vger.kernel.org, Stephen Boyd , Nick Desaulniers , stable@vger.kernel.org, Michal Marek , clang-built-linux@googlegroups.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] kbuild: initialize CLANG_FLAGS correctly in the top Makefile Message-ID: <20190729160412.GA100132@archlinux-threadripper> References: <20190729091517.5334-1-yamada.masahiro@socionext.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190729091517.5334-1-yamada.masahiro@socionext.com> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 29, 2019 at 06:15:17PM +0900, Masahiro Yamada wrote: > CLANG_FLAGS is initialized by the following line: > > CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%)) > > ..., which is run only when CROSS_COMPILE is set. > > Some build targets (bindeb-pkg etc.) recurse to the top Makefile. > > When you build the kernel with Clang but without CROSS_COMPILE, > the same compiler flags such as -no-integrated-as are accumulated > into CLANG_FLAGS. > > If you run 'make CC=clang' and then 'make CC=clang bindeb-pkg', > Kbuild will recompile everything needlessly due to the build command > change. > > Fix this by correctly initializing CLANG_FLAGS. > > Fixes: 238bcbc4e07f ("kbuild: consolidate Clang compiler flags") > Cc: # v4.20+ > Signed-off-by: Masahiro Yamada Reviewed-by: Nathan Chancellor